Toyota Sienna Service Manual: Seat Position Airbag Sensor Circuit Malfunction
DTC B1153/25 Seat Position Airbag Sensor Circuit Malfunction
DESCRIPTION
The seat position airbag sensor circuit consists of the center airbag sensor
assembly and the seat
position airbag sensor.
DTC B1153/25 is recorded when a malfunction is detected in the seat position
airbag sensor circuit.
DTC No. |
DTC Detecting Condition |
Trouble Area |
B1153/25 |
- The center airbag sensor assembly receives a line
short circuit signal, an open circuit signal, a short
circuit to ground signal or a short circuit to B+ signal
in the seat position airbag sensor circuit for 2
seconds.
- Seat position airbag sensor malfunction
- Center airbag sensor assembly malfunction
|
- Seat position airbag sensor
- Center airbag sensor assembly
- Front seat inner belt assembly LH
- Floor wire
|
WIRING DIAGRAM
![WIRING DIAGRAM](images/books/424/44/index.65.jpg)
INSPECTION PROCEDURE
1 CHECK DTC
![CHECK DTC](images/books/424/44/index.66.jpg)
- Turn the ignition switch to the ON position, and wait for at
least 60 seconds.
- Clear the DTCs stored in memory (5).
- Turn the ignition switch to the LOCK position.
- Turn the ignition switch to the ON position, and wait for at
least 60 seconds.
- Check the DTCs (5).
OK:
DTC B1153/25 is not output.
HINT:
Codes other than code B1153/25 may be output at this
time, but they are not related to this check.
Go to step 2
![](images/books/424/44/index.68.gif)
USE SIMULATION METHOD TO CHECK
2 CHECK CONNECTION OF CONNECTORS
- Turn the ignition switch to the LOCK position.
- Disconnect the negative (-) terminal cable from the
battery, and wait for at least 90 seconds.
- Check that the connectors are properly connected to the
center airbag sensor assembly, the seat position airbag
sensor and front seat inner belt assembly LH.
OK:
The connectors are connected.
CONNECT CONNECTORS
![](images/books/424/44/index.70.gif)
3 CHECK CONNECTORS
- Disconnect the connectors from the center airbag sensor
assembly, the seat position airbag sensor and front seat
inner belt assembly LH.
- Check that the connectors are not damaged
OK:
The connectors are not deformed or damaged.
REPAIR OR REPLACE WIRE
HARNESS
![](images/books/424/44/index.72.gif)
4 CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (OPEN)
![CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (OPEN)](images/books/424/44/index.73.jpg)
- Connect the connectors that link the front seat inner belt
assembly LH and floor wire.
- with Side airbag:
Using a service wire, connect A20-4 (LSP+) and A20-3
(LSP-) of connector "B".
NOTICE:
Do not forcibly insert a service wire into the
terminals of the connector when connecting.
- without Side airbag:
Using a service wire, connect A20-3 (LSP+) and A20-8
(LSP-) of connector "B".
NOTICE:
Do not forcibly insert a service wire into the
terminals of the connector when connecting.
- Measure the resistance between the terminals of
connector "E" according to the value(s) in the table
below.
Standard resistance
![Standard resistance](images/books/424/44/index.74.jpg)
Go to step 11
![](images/books/424/44/index.76.gif)
5 CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (SHORT TO B+)
![CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (SHORT TO B+)](images/books/424/44/index.77.jpg)
- Disconnect the service wire from connector "B".
- Connect the negative (-) terminal cable to the battery,
and wait for at least 2 seconds.
- Turn the ignition switch to the ON position.
- Measure the voltage according to the value(s) in the
table below.
Standard voltage
![Standard voltage](images/books/424/44/index.78.jpg)
Go to step 12
![](images/books/424/44/index.80.gif)
6 CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (SHORT TO GROUND)
![CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (SHORT TO GROUND)](images/books/424/44/index.81.jpg)
- Turn the ignition switch to the LOCK position.
- Disconnect the negative (-) terminal cable from the
battery, and wait for at least 90 seconds.
- Measure the resistance according to the value(s) in the
table below.
Standard resistance
![Standard resistance](images/books/424/44/index.82.jpg)
Go to step 13
![](images/books/424/44/index.84.gif)
7 CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (SHORT)
![CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (SHORT)](images/books/424/44/index.85.jpg)
- Measure the resistance according to the value(s) in the
table below.
Standard resistance
![Standard resistance](images/books/424/44/index.86.jpg)
Go to step 14
![](images/books/424/44/index.88.gif)
8 CHECK SEAT POSITION AIRBAG SENSOR
![CHECK SEAT POSITION AIRBAG SENSOR](images/books/424/44/index.89.jpg)
- Connect the connectors to the seat position airbag
sensor and the center airbag sensor assembly.
- Connect the negative (-) terminal cable to the battery,
and wait for at least 2 seconds.
- Turn the ignition switch to the ON position, and wait for at
least 60 seconds.
- Clear the DTCs stored in memory (5).
- Turn the ignition switch to the LOCK position.
- Turn the ignition switch to the ON position, and wait for at
least 60 seconds.
- Check the DTCs (5).
OK:
DTC B1153/25 is not output.
HINT:
Codes other than code B1153/25 may be output at this
time, but they are not related to this check.
Go to step 9
![](images/books/424/44/index.91.gif)
USE SIMULATION METHOD TO CHECK
9 REPLACE SEAT POSITION AIRBAG SENSOR
- Turn the ignition switch to the LOCK position.
- Disconnect the negative (-) terminal cable from the
battery, and wait for at least 90 seconds.
- Replace the seat position airbag sensor.
HINT:
Perform the inspection using parts from a normal vehicle
if possible
![](images/books/424/44/index.92.gif)
10 CHECK CENTER AIRBAG SENSOR ASSEMBLY
![CHECK CENTER AIRBAG SENSOR ASSEMBLY](images/books/424/44/index.93.jpg)
- Connect the negative (-) terminal cable to the battery,
and wait for at least 2 seconds.
- Turn the ignition switch to the ON position, and wait for at
least 60 seconds.
- Clear the DTCs stored in memory (5).
- Turn the ignition switch to the LOCK position.
- Turn the ignition switch to the ON position, and wait for at
least 60 seconds.
- Check the DTCs (5).
OK:
DTC B1153/25 is not output.
HINT:
Codes other than code B1153/25 may be output at this
time, but they are not related to this check.
REPLACE CENTER AIRBAG SENSOR
ASSEMBLY
![](images/books/424/44/index.95.gif)
END
11 CHECK FRONT SEAT INNER BELT ASSEMBLY LH (OPEN)
![CHECK FRONT SEAT INNER BELT ASSEMBLY LH (OPEN)](images/books/424/44/index.96.jpg)
- Disconnect the service wire from connector "B".
- Disconnect the floor wire connector from the front seat
inner belt assembly LH.
- with Power seat:
Using a service wire, connect B18-3 (LSP+) and B18-5
(LSP-) of connector "D".
NOTICE:
Do not forcibly insert a service wire into the
terminals of the connector when connecting.
- without Power seat:
Using a service wire, connect B18-2 (LSP+) and B18-4
(LSP-) of connector "D".
NOTICE:
Do not forcibly insert a service wire into the
terminals of the connector when connecting.
- Measure the resistance according to the value(s) in the
table below.
Standard resistance
![Standard resistance](images/books/424/44/index.97.jpg)
REPLACE FRONT SEAT INNER BELT
ASSEMBLY LH
![](images/books/424/44/index.99.gif)
REPAIR OR REPLACE FLOOR WIRE
12 CHECK FRONT SEAT INNER BELT ASSEMBLY LH (SHORT TO B+)
![CHECK FRONT SEAT INNER BELT ASSEMBLY LH (SHORT TO B+)](images/books/424/44/index.1.jpg)
- Turn the ignition switch to the LOCK position.
- Disconnect the negative (-) terminal cable from the
battery, and wait for at least 90 seconds.
- Disconnect the floor wire connector from the front seat
inner belt assembly LH.
- Connect the negative (-) terminal cable to the battery,
and wait for least 2 seconds.
- Turn the ignition switch to the ON position.
- Measure the voltage according to the value(s) in the
table below.
Standard voltage
![Standard voltage](images/books/424/44/index.2.jpg)
REPLACE FRONT SEAT INNER BELT
ASSEMBLY LH
![](images/books/424/44/index.10.gif)
REPAIR OR REPLACE FLOOR WIRE
13 CHECK FRONT SEAT INNER BELT ASSEMBLY LH (SHORT TO GROUND)
![CHECK FRONT SEAT INNER BELT ASSEMBLY LH (SHORT TO GROUND)](images/books/424/44/index.5.jpg)
- Disconnect the floor wire connector from the front seat
inner belt assembly LH.
- Measure the resistance according to the value(s) in the
table below.
Standard resistance
![Standard resistance](images/books/424/44/index.6.jpg)
REPLACE FRONT SEAT INNER BELT
ASSEMBLY LH
![](images/books/424/44/index.12.gif)
REPAIR OR REPLACE FLOOR WIRE
14 CHECK FRONT SEAT INNER BELT ASSEMBLY LH (SHORT)
![CHECK FRONT SEAT INNER BELT ASSEMBLY LH (SHORT)](images/books/424/44/index.9.jpg)
- Disconnect the floor wire connector from the front seat
inner belt assembly LH.
- Measure the resistance according to the value(s) in the
table below.
Standard resistance
![Standard resistance](images/books/424/44/index.13.jpg)
REPLACE FRONT SEAT INNER BELT
ASSEMBLY LH
![](images/books/424/44/index.16.gif)
REPAIR OR REPLACE FLOOR WIRE
DTC B1152/28 Passenger Airbag ON/OFF Indicator Circuit
Malfunction
DESCRIPTION
The passenger airbag ON/OFF indicator circuit consists of the center airbag
sensor assembly and
passenger airbag ON ...
DTC B1154/38 Rear Airbag Sensor RH Circuit Malfunction
DESCRIPTION
The rear airbag sensor RH circuit consists of the center airbag sensor
assembly and rear airbag sensor
RH.
If the center airb ...
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Engage the 2 claws to install the cigarette lighter
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Absence of Registration Unit/ No Response for Connection Check/ Last Mode
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DESCRIPTION
HINT:
*1: Even if no fault is present, this trouble code may be stored
depending on the battery condition or
engine start voltage.
*2: If the power connector is disconnected after the engine
starts, this code is stored after 180 seconds.
*3: If the ...
Optimal use of the audio
system
On the “Sound Settings” screen, sound quality (Treble/Mid/
Bass), volume balance can be adjusted.
How to adjust the sound settings and sound quality
1, 2, 3 Select “-” or “+” to adjust
the treble, mid or bass to
a level between -5 and 5.
4, 5 Select “Front” or “Rear” ...